A poll for The Wall Street Journal/NBC found that 30pc of those questioned expect the economy to deteriorate over the next year, with 29pc predicting an improvement. Although it's a small difference, economists say it reflects the cumulative effect of high gasoline prices, a still depressed housing market and the uneven recovery in the jobs market.

A slew of data released yesterday did little to dispel the impression that the weakening in gross domestic product seen in the first quarter of the year has extended into the second.

A measure of manufacturing around the Philadelphia region retreated for the first time in nine months in June, and the latest weekly jobless figures showed that more than 400,000 Americans made claims for unemployment benefit in the second week of June.

Wall Street economists are already looking to this month's employment report, which will be released at the start of July, to see whether companies are slowing or abandoning hiring plans in response.

While a weak employment report for May stoked such fears, strong job growth in the first four months of the year has so far convinced most analysts that the world's biggest economy will regain momentum later this year.